Age-related macular degeneration (AMD) is a retinal disease that affects the macula, the central portion of the retina that is responsible for your sharp, central vision. AMD is the leading cause of vision loss in older Americans.
AMD results from gradual deterioration of the retina. The exact cause is unknown, but the primary risk factor is older age. Other risk factors include:
Caucasian or European descent
Excessive sun exposure
Diet low in fruits and vegetables
There are two forms of AMD: dry (non-exudative) and wet (exudative).
Dry AMD is characterized by the accumulation of small, yellow deposits (drusen) and scarring (atrophy) under the retina. It develops slowly and accounts for 90% of cases of AMD. It is called “dry” because there is no leaking or bleeding.
Wet AMD is characterized by the formation of new, abnormal blood vessels that cause leaking or bleeding under and within the retina. It can develop quickly, either from dry AMD and or from a previously-normal retina.
In the early stages, AMD might have no symptoms. As the disease progresses, symptoms include:
Distortion (warping) of straight lines
Blurring, darkening, or loss of central vision
AMD can be diagnosed through a dilated eye exam that shows drusen, scarring, leaking, or bleeding under or within the retina. Ocular coherence tomography (OCT) or fluorescein angiography (FA) can help detect subtle findings.
Once AMD is diagnosed, your doctor might give you an Amsler Grid to monitor for changes at home. Click here to download a grid. Cover on eye and stare at the dot in the middle. If the lines appear wavy, dim, or fuzzy, you could have leaking or bleeding from wet AMD and should call your doctor immediately.
There is no treatment for dry AMD. However, a combination of vitamins called the AREDS2 formula may slow or prevent vision loss. Other recommended measures include avoiding tobacco, wearing sunglasses outside, and eating a balanced diet rich in fruits and leafy, green vegetables.
Wet AMD is treated with anti-VEGF injections that shrink the new, abnormal blood vessels, thereby reducing and preventing the leaking and bleeding that cause vision loss. These injections are delivered into the eye through a very slender needle during an office procedure that takes only seconds and causes minimal discomfort. Watch the video below for more information.